MAPT and Alzheimer disease: To test whether tau‐AC can recapitulate AD or tauopathy phenotypes in vivo, we stereotaxically injected young (3‐month‐old) non‐transgenic mice with either oligomerized tau‐AC‐wt or pseudo‐phosphorylated tau‐AC‐S356D, into the hippocampus (Figure S6A, Supporting Information).